Compound steam-engine



(No Model.) 5 Sheets-Sheet 1.

E. B. BENHAM.

COMPOUND STEAM ENGINE.

" No."898,80 7. Patented Nov. 27, 1888.

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5 Sheets-Sheet 2.

(No Model.)

B. .B. BENH-AM;

COMPOUND STEAM ENGINE.

. No. 393,607. Patented Nov. 27, 1888.

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3n ZJ Subway (No Model.) 5 Sheets-Sh'eet 3.

E. B. BENHAM. COMPOUND STEAM ENGINE.

No. 393,607. Patented Nov. 27, 188.

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(No Model.) I 5 Sheets-Sheet 4.

E. B. BENHAM.

COMPOUND STEAM ENGINE.

No. 393,607. Patented Nov. 27, 1888.

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ELIJAH B. BENHAM, OF HOLYOKE, MASSACHUSETTS.

COMPOUND STEAM-ENGINE.

SPECIFICATION forming part of Letters Patent No. 393,607, dated November 27, 1888.

' Application filed December 19, 1887. Serial No. 258,280. (No model.)

To all whom it may concern.-

Be it known that I, ELIJAH B. BENHAM, a citizen of the United States, residing at Holyoke, in the county of Hampden and State of Massachusetts, haveinvented new and useful Improvements in Compound Steam-Engines,of which the following is a specification.

This invention relates to compound steamengines, the object being to provide a rotary= valve engine of that class of improved construction; and the invention consists in the peculiar construction and arrangement of various parts of the machine, all as hereinafter fully described, and pointed out in the claims.

In the drawings forming part of this specification, Figure 1 is an end and Fig. 2 a side elevation, and Fig. 3 a longitudinal section,of a steamengine constructed according to my invention. Fig. 4 is a longitudinal section of the valve of the engine and of an adjustingring thereon. Fig. 5is a front end elevation of said valve. Fig. 6 is a rear side elevation of the central portion of the cylinder-head of the engine, against which the end of the valve shown in Fig. 5 has a bearing, said Fig. 6 showing the open ends of the steam-ports of the cylinders. Fig. 7 is a perspective view illustrating the central portion of the cylinder;head and certain of the ports therein and the end of the valve which operates in conjunction therewith, said figure having arrows thereon indicating the course of the steamcurrents between said ports and valve.

In the drawings, A is the 'base of the ma chine, and B is the cylinder-head thereof, the latter being bolted to the base A, as shown in Figs. 1 and 2, and having formed thereon two series of steam-cylinders, 17 and 19,0f unequal diameters, but all radiating from a common center, the said cylinders and cylinder-head being constructed in one piece by casting in the usual way and braced and strengthened as shown in Figs. 2 and 3. The said cylinders are properly bored out, and their outer ends are stopped by the heads 18 and 20,which are screwed into the ends of the cylinders or are otherwise suitably secured thereto. The said cylinders are, as above mentioned, of unequal diameters, those indicated by 17 being the smaller and serving as the highpressure cylinders of the engine,and the larger cylinders,

19, serving as the low-pressure cylinders thereof.

The cylinder-head B has a central chamber formed therein, as indicated by J, Fig. 3, which is'open atthe front side of said head. Said head is provided with a cylindrical recess at the rear side of the chamber J, into which is fitted a bushing, 21,0f bronze or other suitable metal, to form a proper bearing for the end of the driving-shaft to which the crank is connected, as below described. As many steampassages c are formed in the cylinder-head B as there are cylinders, said passages extending from the rear side of said cylinders,near their outer ends,in converging lines toward the center of the rear side of said head,or to that part thereof which is covered by the end of the steam-valve, as below set forth. Thesaid passages c serve as both induction and exhaust passages for the cylinders, there being only one of said passages c for each cylinder.

Fig. 6 is an enlarged elevation of the rear side of the cylinder-head, and Fig. 7 shows in perspective the central portion of the rear side of said head, there being shown in both of the last-referred-to figures the ports or ends of said steam-passages 0, those for the passages which lead to the high-pressure cylinders 17 being indicated by a, and those for the passages which lead to the low-pressure cylinders being indicated by b. The said ports a and b are formed in that portion of the rear side of the cylinder-head within the projecting ring 1 and said ports are all in the same plane, but located at different distances from the center of said head-that is to say, the ports a are farthest from the center of the cylinder-head and equidistant from said center, and the ports I) are nearest said center and also equidistant therefrom.

One end of the drivingshaft 2 terminates within the chamber J of the cylinder-head and has secured thereon the crank 3, the crankpin 4 being secured to or a part of the latter. The pistons 16 are of any ordinary suitable construction,and are provided with the pistonrods 14, each having a laterally-extending arm, .15, on the end thereof adjoining the crankpin. A sleeve, 5, of bronze or other suitable bearing metal, having a flange on one end, as shown, and having its outer end screw-thread- IOO ed and provided with the oil-holes 0 through its sides, is placed on the crank-pin 4, and the ends of said pistonrods 14 are united around said sleeve 5 and secured in that position by a metal ring, 1;, placed over the arms 15 on the ends of the piston-rods. The said ring 1) is held in position on said arms by a metal cap, 6, which is screwed on the end of said sleeve 5, and said cap 6 is centrally perforated to re ceive an oiling connection, as below described,whcreby the crank-pin and its imme diately-connected parts are k cptautomatically lubricated. The said chamber J within the cylinder-head is covered by a cap, 12,which is bolted to the front side of said head, as shown in Figs. 1, 2, and 3. and said cap has centrally thereon the oitcnp stud 13, a passage being made through the upper side of said stnd,with which a longitudinal passage in the cap communicates, and an oil-cup, 10, is secured to the upper side of said stud, as shown, and communicates with said longitudinal passage in the cap or with an oil-conduit placed therein, said conduit being indicated by 9 in Fig. 3, and consists of a metallic tube having perforations through its sides near each end, which perforations in one end thereof communicate with the outlet from said oil-cup 10. Said oil-conduit 9 extends more or less into said chamber J.

A chambered oiling'erank, 7, has a nipple, S, screwed thereto near one end, which communicates with an oil-passage in said crank, and the said conduit 5) enters the latter near its opposite end, and the oitperlbrations in the sides of said conduit communicate with the oil passage or chamber within said crank 7. One end of said nipple8 enters the perforated end of the above-referred-to cap 6, which screws onto the end of said crankpin sleeve 5. The said oiling crank 1 has one side thereof bearing against the inner side of the cap 12, whereby it is held in proper position to be rotated by its connection by one end with said cap 6, and in consequence of said connection the nipple-bearing end of said crank 7 has a rotary motion coincident with thatofthe crank pin, and it swings on the inner end ofsaid conduit 9. By reason of the said rotary motion which is given to the said oiling-crank 7 oil, which runs from the oil-cup 10 through the conduit 9 into the interior of said crank, is discharged through said nipple S into the intcrior ol' the cap 6 and directly against the end of the crank-pin 4., and from thence the oil works between the crank-pin and the sleeve 5. and emerges from the latter through the oil-holes o, and serves to lubricate the outer side of said sleeve, so that there shall be no friction between thelatter and the ends of the piston-rods, nor between said sleeve and the crank-pin.

From the above description it is seen that the construction of the cylinderhead B, the pistons, and their connections with the crank,

parts of a compound engine, is of exceeding simplicity, and consequently comparatively low cost, and embodies great solidity and strength. The said arrangement of alternately high and low pressure cylinders radiating from a common center is made practicable by the employment ofthe below-described peculiarlyconstructed steam-valve, which has a continuous rotary movement in one direction in engagement with the side of the cylindcnhead, in which said ports a and b are, its end cover iug the latter. Said valve, as below described, serves to admit steam under high pressure, first, to the high-pressure cylinders 17 in succcssion,t-hen to receive the exhaust steam from the latter and transfer it to the low-pressure cylinders 18, and finally to receive in a pas sage therein the exhaust-steam from the lastna-med cylinders and conduct it to an exhanstchamber, whence it escapes to the open air.

The valve-case of the engine consists of the cylindrical sections 22 and 23. the former being rigidly bolted to the rear side of the cylinder-head B and the section 23 to the end of said section 22, as shown in Figs. 2 and 3. Said valve-case sections are constructed internally to adapt them to receive and to co-operate with the valve D, as below described. The construction of said valve D, which controls the flow of the steam to and from the cylinders of the engine, as aforesaid, is clearly shownin Figs. 4, 5, and 7. Said valve consists ofa cylindrical head having a somewhat reduced diameteralittlebackofitslarger bearing cnd,and from said head rearward extends a tubular portion, as shown. Said valve has a shaft-passage, a, through it from end to end to receive the driving-shaft 2. In Figs. 5 and 7 are illus trated the front end of the valve, and when the latter is placed in the engine in operative rclation to the head B, as shown in Fig. 3, said end of the valve enters within the ring y and bears closely against that portion of the side of the head within said ring in which the ports a and I) are formed and covers the latter,'and the hub 30 on the head then enters the recess in in the end of the valvc,and serves to impart steadiness to its rotary movement by keeping it always in line, and thus tends to keep the end of the valve in the same plane as the side of the head against which it bears and prevents the escape of steam from between those parts.

The head of the valve D has the main steampassage 0 formed therein,extending from about midway between the ends of said head to the bearing end thereof, said passage extending circumferentially nearly half-way around the valve-head, as shown, said passage communieating with the ports a of the high-pressure cylinders 17. The said valve has formed therein the exhaust-steam passage K, which extends quite through the head of the valve and cireumferentially nearly half-way around the head,said exhaust-passage communicating embracing, as it does, the cylinder and piston l with the ports I) of the low-pressure cylinders 19. The head of valveDis also provided with a, so to speak, transfer steam-chamber, h, whose function it is to receive the exhauststeam from said high-pressure cylinders and permit it to flow therethrough into the ports I) of the low-pressure cylinders,and to that end said chamber is made of the irregular form shown in Figs. 5 and 7. Looking at Fig. 5, the upper portion of said chamber there shown, or that having the greater radius, communicates with the outer ports,a,and the lower portion thereof, or that having the lesser radius, communicates with the inner ports, I), and there being free communication all around in said chamber exhaust-steam entering it from the ports a is instantly transferred to the ports I), and thence into the low-pressure cylinders to act on the pistons thereof. It will be seen that said two portions of the chamber h having the greater and lesser radii are concentric, respectively, with the open ends of the steam-passage e and the exhaust-passage K. The said valve-case section 22 has a circular steam-chamber, f, therein with which the rear end of the steam-passage e of the valve communicates, whatever may be the position of the latter, said chamber receiving steam through the inlet-pipe 28. An adj ustiug'sleeve, 26,0f cylindrical form, is screwed into the said section 22 and surrounds the rear portion of the head of the valve (see Figs. 3 and 4) and engages with a shoulder or undercut annular groove around said head, the object of said sleeve being to provide means for holding the front end of the valve-head closely against the cylinderhead and to adjust the valve longitudinally to take up for wear and avoid unnecessary friction between the valve and head. Said sleeve 26 has the end thereof which engages with said undercut annular groove in the valve-head sharpened or beveled to fit said groove, and thereby a joint is formed between the parts, which more effectually prevents steam from escaping from the said steamchamber f. The said sleeve 26 has a flange on its rear end,in which are several perforations, as shown in Fig. 4. The border of said flange is located opposite an opening, L, in the upper side of the valve-case section 23, through which a pointed tool or bar may be passed to have its end inserted in said perforations and act as a lever for turning said sleeve to adjust the valve, as aforesaid. The said exhaustpassage K in the head of the valve D continues substantially in the form shown in Fig. 5 from the end of the valvehead a little more than half-way to the rear end of said head, and then has the form of an annular chamber within said rear end, (see Fig. 3,) which has free communication with the exhaust-chamber w in the rear end of said case-section 22, from whence the exhaust-steam escapes through the pipe 29. (See Fig. 2.) The arrows opposite the steam inlet and outlet openings in said section 22 indicate the direction of the steanrcurrents therethrough.

A collar, d, surrounds the tubular portion of the valve D just forward of the end of the rear valve-case section,23, and serves to direct the exhaust-steam,\vhich comes from the pars sage K, in a lateral direction and prevent 1t from striking directly the end of said section, thereby more or less obviating any tendency to leakage between said case and valve which may exist. A packing nut. 24, is screwed into the rear end of the said case-section 23 and holds suitable packing in an annular groove near the end of said section, whereby leakage is prevented at that point, and a second packing-nut, 31, is placed on the shaft 2 and 1S screwed into the end of the valve D against suitable packing in the annular groove 9 therein, whereby any leakage of steam around the shaft is prevented.

A collar, 25, is rigidly fixed on the rear end of the valve D, in which is a clutch-pin, 32 having an engagement with a collar, 33, which is secured on the shaft 2, whereby the valve D is given a constant rotary motion in consonance with said shaft.

The driving-pulleyE is fixed on shaft 2 near the rear standard, F, as shown in Fig. 3.

In Fig. 7 the parts of the cylinder-head B and the valve D there shown, together with the arrows between said parts, indicate the movements, successively, of the live and the exhaust steam between the valve and said head, which is as follows: The engine being at rest, steam is turned on and first rushes through the passage 6, on the line of the arrow so, into the ports a, covered by the open end of said passage, and the steam acts on the highpressure cylinders 17, moving the pistons inward and starting the shaft 2. At or near the end of said inward movement the rotary motion of the valve brings a portion of the transferchamber h opposite said ports which received steam, and the exhaust therefrom enters said transfer-chamber, as indicated by the arrow 2. The said exhaust-steam circulates around said transferchamber and escapes therefrom into one or more of the ports b communicating with the low-pressure cylinders 19, as indicated by the arrow m, and, having acted on the piston or pistons thereof, it finally escapes through the exhaust-passage K, as indicated by the arrow 2:, and, passing through said passage, escapes as above described.

\Vhat I claim as my invention is- 1. The cylinder-head 13, having the alternating high and low pressure series of cylinders l7 and 19 thereon, said high and low pressure cylinders having communication through steampassages in said head with a separate series of ports, a and b, for each of said series of cylinders,twovalve-chamber sections,

22 and 23, secured end to end on one side of said cylinder-head opposite said ports and provided with a receiving and an exhaust steam chamber, as described ,the cylindricallyformed valve D, capable of a rotary movement in said sections, having one end covering the said ports, and having formed therein a steam-passage forming a communication between said receiving chamber and high-pressure cylinder-ports, an exhaust-passage forming a communication between the ports of said lowpressure cylinders and said exhaust chamber, and a Iransfer-chamber forming communication between said high and low pressure cylinder-p0rls, combined with a driving-shaft, 2, extending through and connecting with said valve, and suirable pistons, as described, operating in said cylinders and connected to a crank on said shaft, substantially as set forth.

2. A compound steam-engine consisting ofa cylinder-hcad having two series of steam-cylinders thereon of unequal diai'neters side by side and radiating from a common center and communicating bya single steanrpassage for each cylinder, with two series of ports on one side of said head at different radial distances from the centermombined Willi a valve-chamber extending from one side of said cylinderhead, a crank-shaft, suitable pistons Operating in said cylinders and connected with said shaft, and a valve having one end covering said ports,attached to and having a concentric rotary motion in consonance with said shaft, and having direct and exhauststeam passages, and a transfer steam chamber therein, as described, coiunninieating with both of said series of ports. substantially as set forth.

A compound sleanrengiuecylindcrliead having high and low pressure cylinders radiating from a common center, having the steamports for said cylinders divided into two circular groups at different radial distances from the center, combined with a crankshaft, pistons connected to said crank, and a valve rotating with said shaft having one end covering said ports, a passage therein conducting steam through one series of said ports to said highpressure cylinders, a chamber in said valve transferring steam from the high to the low pressure cylinders, and apassage in said valve through which steam is exhausted from the latter named cylinders, substantially as set forth.

4.. In combination, the cylinder head B, having the ports I), communicating with the low-pressure cylinders of the engine, the valveeliamber section 22, and the valve D, having therein the exhaustpassage K, having a segmental opcning at the end of the valve communicating with said ports and terminating rearwardly in an annular chamber in said valve communicating with the cxhaust-chamber win said section, substantially as set forth.

5. In combination, the valve-chamlmr section 22, the valve I), having an undercut annular groove thereon, and the adjustingslecve 26, screwing into said section and having a beveled end engaging with said groove, substantially as set forth.

6. 'lhecrankpin 4, the sleeve 5, having one end screw-thremled, the piston-rods 14. engaging with said slecve and having laterallyextending arms, and the ring 12, inclosing said arms, combined with the cap (3, screwed onto said sleeve and against said ring, substantially as set forth.

ELIJ AH B. BENHAM.

Witnesses:

G. M. CHAMBERLAIN,

' H. A. Gnarm. 

